How to install and Configure NTP client on CentOS/RHEL to Synchronize the Clock

NTP, Network Time Protocol, it is an Internet protocol used to synchronize the clocks of computers or servers to some NTP server on internet or intranet. In CentOS, it is very easy to install and configure the ntp client.

Install your NTP client using yum command:

    [root@server ~]# yum install ntp
    Loaded plugins: fastestmirror
    Loading mirror speeds from cached hostfile
     * addons: ftp.oss.eznetsols.org
     * base: ftp.oss.eznetsols.org
     * epel: ftp.cuhk.edu.hk
     * extras: ftp.oss.eznetsols.org
     * updates: ftp.oss.eznetsols.org
    Setting up Install Process
    Resolving Dependencies
    --> Running transaction check
    ---> Package ntp.x86_64 0:4.2.2p1-9.el5.centos.2.1 set to be updated
    --> Finished Dependency Resolution
    
    Dependencies Resolved
    
    =====================================================================================
     Package      Arch            Version                            Repository     Size
    =====================================================================================
    Installing:
     ntp          x86_64          4.2.2p1-9.el5.centos.2.1           base          1.3 M
    
    Transaction Summary
    =====================================================================================
    Install       1 Package(s)
    Upgrade       0 Package(s)
    
    Total download size: 1.3 M
    Is this ok [y/N]: y
    Downloading Packages:
    ntp-4.2.2p1-9.el5.centos.2.1.x86_64.rpm                       | 1.3 MB     00:04
    Running rpm_check_debug
    Running Transaction Test
    Finished Transaction Test
    Transaction Test Succeeded
    Running Transaction
      Installing     : ntp                                                           1/1
    
    Installed:
      ntp.x86_64 0:4.2.2p1-9.el5.centos.2.1
    
    Complete!
    

Configure your ntp.conf file and pointing to your NTP server

    [root@server ~]# vi /etc/ntp.conf
    
    server 0.centos.pool.ntp.org     //set this to your primary NTP server  - Line 17
    server 1.centos.pool.ntp.org     //set this to your Secondary NTP server (Optional)  - Line 18
    server 2.centos.pool.ntp.org     //set this to your tertiary  NTP server(Optional)  - Line 19
    

As for example :

    server ntp1.server.local
    server ntp2.server.local
    

Restart your ntp client using below command:

    [root@server ~]# service ntpd restart
    

or

    [root@server ~]# /etc/init.d/ntpd restart
    

Test your ntp client status whether properly configured or not by running below command:

    [root@server ~]# ntpq -p
    

How to Reset the Directory Manager Password on RHEL 7 / CentOS 7
How to Reset the Directory Manager Password on RHEL 7 / CentOS 7

It is best practice to remember passwords, but because too many passwords, sometimes we forget. We are not encouraged to write the password on any paper or share the password...

How to Find Big Files Size on Linux RHEL/CentOS
How to Find Big Files Size on Linux RHEL/CentOS

As the linux administrator, sometimes we have to identify which files are most take much space in the linux server resulting in low free space. Low disk space can also...

Why Linux users should worry about malware and what they can do about it
Why Linux users should worry about malware and what they can do about it

Don’t drop your guard just because you’re running Linux. Preventing the spread of malware and/or dealing with the consequences of infection are a fact of life when using computers. If...

How to Reset Forgotten Root Password on Linux RHEL 7 / CentOS 7
How to Reset Forgotten Root Password on Linux RHEL 7 / CentOS 7

This short howto will explain the steps to reset a lost root password or to reset a forgotten root password on Linux RHEL 7 or CentOS 7. Basically, we will...

How to Update CentOS or Upgrade CentOS to the Latest Version
How to Update CentOS or Upgrade CentOS to the Latest Version

Recently, the latest version of CentOS 7.3 was released. All users of CentOS 7.0, 7.1 and 7.2 can upgrade their system to the most recent. This quick guide will explain...

How to Change your WordPress Username, Nickname and Display Name in MySQL
How to Change your WordPress Username, Nickname and Display Name in MySQL

After you create an account log in WordPress, you may want to change your WordPress username, as appropriate or due to security reason. However, you can not do this from...

How to Enable SSH Root Login on Ubuntu 16.04
How to Enable SSH Root Login on Ubuntu 16.04

As what we wrote in the previous article on how to allow SSH root on Ubuntu 14.04, after installing a fresh new copy of Ubuntu 16.04 LTS, we find that...

How to Change UUID of Linux Partition on CentOS 7
How to Change UUID of Linux Partition on CentOS 7

UUID (Universally Unique IDentifier) should be unique and it is used to identify storage devices on a linux system. If you cloned a virtual machine from vCenter, the metadata containing...

Leave a Reply

Your email address will not be published. Required fields are marked *